272 IOWA ACADEMY OF SCIENCES. 



cate unusually good water, with the exception that in the 

 Curtiss well and the Sexton well gas was produced, but 

 this undoubtedly came from the surface soil. The spring 

 water showed no gas whatever, nor was any obtained from 

 the hydrant which was next to the spring. The samples 

 and plates were carefully plated. 



BACTERIA FOUND IN OTHER WATER SUPPLIES. 



We have found quite commonly in all of our waters the 

 B. Uquefaciens-fliiorescens. The Tyrothrix of Duclaux is 

 certainly also common. Most attention has been given to 

 the chromogenes. The common genera of Bacillus and 

 Micrococcus w^ere represented, and of the these the Micro- 

 cocci were found more frequently than the Bacilli of these 

 Micrococcus roseus-flavus, Hefferan, M. agilis, A. Cohn, and 

 others were found. 



BACILLUS TYPHOSUS IN WATER. 



Now, as to the relative vitality of Bacillus typliosus in 

 water; many determinations have been made, and it 

 would not be strange if the Bacillus tt/phosus should not be 

 found in water. 



It is usually held by sanitarians that water is the most 

 frequent source of infection. The evidence of B. typhosus 

 in water, in most cases, is circumstantial; but I recall a 

 case where Dr. Ravold found it in Mississippi river water, 

 and bacteriological journals report cases of its occurrence 

 in wells and streams, but the reported findings of the 

 organism under such circumstances are not numerous. It 

 is very evident that the typhoid fever bacillus will not 

 grow in the ordinary media with other pathogenic o-gan- 

 isms, nor are the special media much more satisfactory. 

 It is evident from the results obtained from several investi- 

 gators that not much can be expected from the organism 

 after four weeks. It is certain that the typhoid fever 

 organism will not multiply freely in water. 



MILK AS A SOURCE OF CONTAMINATION. 



As to the bacteria found in the milk supply, an investi- 

 gation has been made, but this work was not completed, 



